The normal process for producing copper wire rod is to obtain first a rectangular cross section bar, the cross area of which is reduced by means of rolls. The rolls are in above-below and lateral alternate pair systems. By passing through each pair system, the rod area is reduced in a predetermined percentage and this is called reduction step.
During the process of manufacturing copper wire rod from a bar, the flaws that appear in said bar can worsen in each reduction step. Generally, these flaws appear in continuous form, normally said flaws are detected when they cause problems in subsequent processes (such as wire stretching) causing economic losses.
Because of the high demand for wire rod, the manufacturers have tried to monitor the flaws of the bar in real time in order to take corrective actions. However, in the case of bubbles and cracks the normal inspection procedure is to take bar samples with the consequent stoppage of the production process. This is because there is no device that can examine said flaws in real time in a line process.
The analysis of the laboratory samples suggests the modification of operating conditions, but it is not possible to correlate the new operating conditions to the increase or decrease of the bubble and crack number without stopping again the manufacturing process.
To solve this problem inspection devices based on CCD linear elements have been developed. The main problem with this type of devices is the difficulty to synchronize the input of images with the speed of the bar. Besides, it is impossible to use a monitor to observe the zone of the bar which is being examined and the existence of flaws.
With regard to the mentioned above points, the applicant has developed a device to measure and count said flaws in real time. The device which is the object of the present invention has the capacity to count and measure the bubbles that are located near the upper surface of the bar during the wire rod production process. Besides, said device counts the cracks that are generated on the side of the bar during the reduction step in the zones where the largest percentage area reduction is performed, through one or more video cameras.
It is thus an object of the present invention to offer a sensor device to count and determine the size of cracks and bubbles in copper bars during tapping, said device can detect said cracks and bubbles without the need to stop the tapping process.
A further object of the present invention is to offer a novel and reliable method of rapid and precise detection which is easy to handle and without economic losses.